Method for producing of concrete with controllable density

Abstract

A method for producing a concrete with a controllable density, which at the density of 1200 kg/m 3 has a compression strength of at least 3.5 MPa and after that linearly increases to at least 19 MPa at 2,000 kg/m 3 , characterized in mixing a base concrete mixture mainly consisting of cement and water with a porousity mixture mainly consisting of cement, water and a foaming agent so that the foaming agent constitutes at least approximately 5% by volume of the porousity mixture, and that the resultant mixture of the base concrete mixture and the porousity mixture is moulded in a conventional manner.

We claim: 
     
       1. A method for producing a concrete with controllable density, which at the density of 1200 kg/m 3  has a compression strength of at least 3.5 MPa and after that linearly increases to at least 19 MPa at 2,00 kg/m 3 , characterized in mixing a base concrete mixture mainly consisting of cement and water with a porousity mixture mainly consisting of cement, water and a foaming agent so that the foaming agent constitutes at least approximately 5% by volume of the porousity mixture, and that the resultant mixture of said base concrete mixture and said porousity mixtures is moulded in a conventional manner. 
     
     
       2. A method for producing a concrete according to claim 1, characterized in that the finished concrete has closed pores with a size which are generally below 3 mm. 
     
     
       3. A method for producing a concrete with controllable density, which at the density 1200 kg/m 3  has a compression strength of at least 3.5 MPa and at the density 2000 kg/m 3  has a compression strength of at least 19 MPa, said method comprising the steps of mixing a concrete mass mainly consisting of cement and water and a porousity mixture mainly consisting of cement, water and a foaming agent, the porousity mixture including at least 5% foaming agent by volume, and thereafter molding the resultant mixture. 
     
     
       4. A method as set forth in claim 3 wherein the concrete has closed pores, substantially all of which are below 3 mm in size. 
     
     
       5. A method for producing a concrete mass having a density between 300 kg/m 3  and 2000 kg/m 3  and having a compression strength, at a density of 1000 kg/m 3 , of at least 3.0 MPa and that increases to at least 12, MPa at a density of 1600 kg/m 3 , the method comprising the steps of: (1) mixing a base concrete mixture of cement and water,   (2) mixing a porousity agent of cement, water and a foaming agent,   (3) mixing the porousity agent and the base concrete mixture, and   (4) moulding the resultant concrete mass.   
     
     
       6. The method as set forth in claim 5 wherein the vct of the base concrete is approximately 0.45 and wherein the vct of the porousity agent is approximately 0.48. 
     
     
       7. The method as set forth in claim 5 wherein the resultant concrete mass has therein a plurality of closed pores substantially uniformly distributed throughout said mass and wherein each of said pores has a diameter of approximately 3 mm.